It seems to me that any addendum signed later after the initial lease may create a messy situation. 

Quote from @Roxanne Whitaker: Please be aware if you buy an investment property and do not live in MD, when you go to sell it you will pay an 8% tax at settlement. 

The best thing you can do is familiarize yourself with Housing Quality Standards (HQS) and ensure your property meets them before your initial inspection.

Their pay-as-you-go model allows flexibility, so you only pay for what you need.

House gets foreclosed on when a borrower is not paying its debt obligations - typically its mortgage.buying foreclosures is not for the faint of heart as you have no idea of the interior of these properties lastly while it can be beneficial also realize if there are a lot in an area those homes are the new comps when trying to sell so it lowers home values in an area 

Are there specific market indicators or property traits I should be paying attention to?

Even a single error could cost you more than years of property management fees.Understanding Tenant BehaviorProperties don’t pay rent—tenants do.

Most lenders require proof of someone else paying the note for around 9-12 months so that the debt isn't counted in their DTI calculation.

So depending on how much you pay for it, you can assess your cashflow.

The time allotted on the initial contract was ample time for the buyer to close.